I think most people here have touchscreens for controlling their PC's...
I have steering wheel controls in my car, but I was thinking about going with the SWI-X setup...
Maybe you can convince me otherwise...

I have a touchscreen too but it's handy for controlling some of the basic features such as play/pause, next/prev track and in some cases actually manipulate the headunit display (depends on the headunit). It's great for people like me who don't want to mess up the dash too much or install aftermarket sound systems in a nearly new car that already has a decent one.

In case you are wondering my touchscreen is going into the SatNav housing which itself is aftermarket. It's just a drop-in replacement though so means I can get the car back to standard pretty easily.